Device for heating a fluid

ABSTRACT

The invention relates to a device ( 1 ) for heating a fluid ( 9 ), with a housing ( 2 ) comprising a housing shell ( 3 ), a housing base ( 4 ) and a housing cover ( 5 ), with at least one inlet opening ( 11 ) and at least one outlet opening ( 13 ) for the fluid ( 9 ), and at least two electrodes are disposed in the housing ( 2 ) at a distance ( 25 ) apart from one another, which are each electrically conductively connected to a pole of at least one pulse generator ( 20 ). The pulse generator ( 20 ) is configured to emit variable voltage pulses.

The invention relates to a device for heating a fluid, with a housing comprising a housing shell, a housing base and a housing cover, with at least one inlet opening and at least one outlet opening for the fluid, and at least two electrodes are disposed in the housing at a distance apart from one another, in particular at least one anode and at least one cathode, which are each electrically conductively connected to a pole of at least one pulse generator, a heating system comprising at least one device for conveying a first fluid, at least one device for heating a fluid, at least one heat exchanger in which the heat generated by the fluid is transmitted to another fluid, as well as the use of the device for heating a fluid.

Methods of electrical heating are already known from the prior art. They can be sub-divided into resistance heating, arc heating, induction heating systems, dielectric heating systems, electron heating systems, laser heating systems and combination heating system. For example, RU 21 57 861 C discloses a system for recovering thermal energy, hydrogen and oxygen, which operates on a physical-chemical based technology. This device comprises a housing made from a dielectric material, which is provided with an integrally cast, cylindrically conical cam with an end-to-end orifice which, together with the housing, constitutes the anode and cathode chamber. The anode is provided in the form of a flat ring with orifices which sits in the anode chamber and is connected to the positive pole of the power supply source. The rod-shaped cathode is made from heat-resistant material and is inserted in an externally threaded rod, together with which it can be centered in the orifice in the cover by means of a threaded orifice in the housing leading to the interelectrode chamber and is connected to the negative pole of the power supply source. The inlet connectors for initiating operation are disposed in the middle part of the anode chamber.

The disadvantage of the methods and devices known to date as a means of electrically heating solid bodies, liquids and gases resides in the high energy intensity of the heating process. Above all, this results in poor levels of efficiency.

Accordingly, the objective of this invention is to propose an option for heating a fluid which is more economical.

This objective is achieved by the invention, independently in each case, by the device for heating a fluid mentioned above, the heating system and the use of the device proposed by the invention as a means of heating a building, and the pulse generator is configured to emit variable voltage pulses, and the heating system comprises at least one device for heating a fluid as proposed by the invention.

Due to the voltage pulses applied to the fluid, a vibrating behavior is excited in the molecules in the system, i.e. in the molecular structure of the fluid. The prevailing pattern of the molecules in the fluid is destroyed as a result and the molecules strive to restore this ordered state, which is dependent on the respective temperature of the fluid. It was observed that the degree of efficiency with which the fluid is heated with the aid of the voltage pulses could be improved if uniform pulses were not transmitted over time, i.e. voltage pulses with a constant amplitude and/or constant pulse duration, and if instead, the pulse generator emitted variable voltage pulses. As a result of this variability, the behavior of the fluid, namely its attempt to establish a specific order in the system, is constantly thwarted. This enabled the efficiency of the device to be improved.

It is of advantage if the pulse generator generates voltage pulses with an amplitude selected from a range with a lower limit of von 330 V, in particular 500 V, and an upper limit of 1500 V, in particular 1200 V. Precisely this range is of advantage if water is used as a heat-carrying medium, i.e. as fluid, with a view to improving heating.

In order to prevent the molecules from establishing a specific ordered state in the fluid, the pulse generator may comprise a random number generator, which may be based on hardware or software, by means of which the voltage pulses can be configured on a variable basis.

Based on a preferred embodiment, the pulse generator generates voltage pulses with a steep rising flank of at least 25 V/μs. A preferred embodiment in this respect is one where the pulse generator is configured to emit rectangular voltage pulses. Due to the steep rising flank of the pulses used to obtain maximum amplitude, the energy can be transmitted to the system, i.e. fluid, in the manner of an “explosion” which enables premature restructuring of the molecules to be prevented more easily, thereby enabling a higher energy yield to be obtained.

The pulse generator may be configured so that it emits voltage pulses at a pulse frequency selected from a range with a lower limit of 20 Hz, in particular 800 Hz, preferably 2530 Hz, and an upper limit of 20 kHz, in particular 11 kHz, or voltage pulses with a pulse duration selected from a range with a lower limit of 2 ns, in particular 10 ns, and an upper limit of 10 its, in particular 5 μs, or generates voltage pulses with a pulse pause selected from a range with a lower limit of 2 μs, in particular 5 μs, and an upper limit of 20 μs, in particular 8 μs. Again, effectiveness was improved as a result of these individual variants of the invention, either individually or used in any combination with one another, if using water as a fluid for carrying heat.

To prevent the molecules of the fluid from assuming an ordered state, the pulse generator is configured to generate variable pulse pauses so that the voltage pulses are applied at a variable frequency.

It is of advantage to provide at least one other electrode in the reaction chamber, preferably at least two other electrodes, which is or are electrically conductively connected to a power source, so that ions are emitted into the fluid by means of this/these additional electrode(s) in the reaction chamber, as a result of which the conductivity of the fluid can be selectively influenced, thereby enabling transmission of the voltage pulses via the cathode and the anode to the fluid in order to heat it can be improved, rather than adding a conductive salt to the fluid, which does enable conductivity to be influenced but depends on the concentration of conductive salt added so that the conductivity assumes a specific value. By contrast with this approach, the conductivity can be controlled or regulated or influenced by means of the other electrode(s). This is of particular advantage if the device proposed by the invention is used in a heating system because the primary circuit of such heating systems in which the device is incorporated usually forms a closed system after initial commissioning except when compensating the pressure or generating overpressure. By influencing conductivity from outside, including during operation, the invention offers the possibility of operating the device with greater efficiency.

The other electrode or the at least two other electrodes are preferably made from a material selected from a group comprising Pd, Pt, Ti, Rh, Au, Ag, Ni, Cu, Ir, Fe, V, Nb, Ta and their alloys, in particular alloys of at least two of these elements in conjunction with one another, and the elements Pd, Pt, Ti, Rh and their alloys are preferred. This results in better stability of the system in the device, especially as regards the service life of the at least one other electrode. Surprisingly, however, an improvement in the degree of efficiency of the device, i.e. the heating power, has also been observed compared with electrodes made from other materials.

The other electrode or at least one of the two other electrodes is preferably disposed in the region of one of the at least two electrodes, in particular the anode or the cathode. As a result of this disposition of the other electrode or at least one of the other electrodes, the fluid in the reaction chamber to which voltage pulses are applied moves into the region of the at least one other electrode shortly after being subjected to the voltage pulses already, so that the molecules of the fluid in this region assume a higher energy state or have a higher energy content due to having been subjected to the voltage pulses so that the ions generated by means of the two other electrodes are improved, in addition to which an effect is produced whereby some of the energy transmitted to the molecules of the fluid is consumed in order to generate the ions and is not available for partially evaporating the fluid, which makes it easier to prevent the formation of larger gas or vapor bubbles on the millimeter scale in the fluid which would impair the degree of efficiency, i.e. the effectiveness of the device.

In practice, it has been found to be of advantage if a distance between the at least two other electrodes is at least 10%, in particular at least 25%, of the length of the reaction chamber, which is defined by the housing. In this respect, the length should be understood as meaning the direction of the longitudinal mid-axis of this reaction chamber and formed by the region in which the at least two electrodes are disposed, in other words specifically the at least one anode and the at least one cathode. This geometric alignment of the two other electrodes enables homogenization of the ions in the fluid emanating from the electrodes to be improved because a sufficiently large mixing run or a sufficiently large volume is available in the housing, i.e. in the reaction chamber, for homogenizing the fluid. Furthermore, it is also possible to apply a relatively low voltage between these two other electrodes so that the process of generating the voltage pulses between the at least two electrodes, in particular the anode and the cathode, is not negatively affected.

It may also be that the other electrode or the at least two other electrodes are bar-shaped with a diameter of at most 30%, in particular at most 20%, of the smallest dimension of at least one of the at least two electrodes, in particular the at least one cathode. On the one hand, this or these other electrode(s) therefore require a relatively small amount of space and on the other hand, the associated small surface of the other electrode(s) is better able to prevent ions being generated in the fluid in too high a concentration so that the device can be more easily controlled because low fluctuations which might occur in the electrical parameters with which the other electrode or the two other electrodes is or operated do not have any significant influence on the fluid.

Based on the preferred embodiment, the power source for the at least two other electrodes is a constant voltage source so as to ensure that the ions are generated continuously in the system.

Based on another embodiment, the other electrode or the at least two other electrodes are activated in an electrolyte bath by means of voltage pulses with an amplitude selected from a range of 5 V to 50 V, in particular 10 V to 20 V, preferably with 15 V, (direct current) and a pulse duration selected from a range of 1 μs to 10 μs, in particular 3 μs to 5 μs, at a current intensity selected from a range with a lower limit of 2000 A, in particular 4000 A, and an upper limit of 8000 A, in particular 6000 A. As a result of this activated surface, it was found that a significant improvement could be obtained in terms of the effectiveness of the two other electrodes and hence an increase in the degree of efficiency of the device.

It is also of advantage if the fluid contained in the reaction chamber, i.e. in the device, is water and an electrolyte is contained in this water so that a certain ability to conduct is already imparted to the fluid, thereby enabling the energy consumption via the two other electrodes to be reduced.

The electrolyte preferably contains water glass (Na₂SiO₃), at least one lye, in particular KOH, distilled or de-ionized water, and optionally Na₂SO₃ and/or K₂SO₄, which offers advantages in terms of generating ions via the two other electrodes on the one hand whilst ensuring that electrolyte contained in the device will not cause environmental problems on the other hand.

The at least two other electrodes may be disposed in the direction of a longitudinal extension of the housing and coaxially with one another in the housing, thereby offering advantages in terms of smoothing the fluid after applying the voltage pulses due to the small active surface between the two other electrodes, which is essentially limited to the mutually opposite end regions of the other electrodes.

In order to improve the effectiveness of the process of applying voltage pulses to the fluid in the region of the housing in which the electrodes are disposed, at least one of the at least two electrodes, in particular the anode, is based on a basket-shaped design, and in another embodiment, it is preferable if at least one of the least two electrodes is disposed at least partially inside the basket-shaped electrode, in particular the cathode is disposed at least partially inside this basket-shaped anode. This enables a more homogeneous distribution of the charge carriers introduced into the fluid to be improved.

It was also observed that the effectiveness of the device and as a consequence the heating system can be improved if the distance between the at least two electrodes, in particular between the cathode and the anode, is at least 5mm, in particular at least 7 mm. This is also of particular importance with respect to the formation of bubbles so that the selected distance has a supporting effect on the smoothing section.

Based on the preferred embodiment of the device proposed by the invention, the housing shell is of a cylindrical design, leading to a positive flow behavior of the fluid by avoiding edges, etc., thereby avoiding eddying in the fluid.

Another approach is to dispose at least one of the least two electrodes in the housing so that it can be moved in a relative displacement towards the other electrode, in particular the anode is moved relative to the cathode and/or the cathode relative to the anode. This enables the distance between the at least two electrodes to be readjusted, even during operation of the device, in order to improve the effectiveness of the device proposed by the invention.

Furthermore, at least one laser may be provided in the reaction chamber. The ions originating from the two other electrodes or from the added electrolyte can be activated by the laser, thereby enabling the conductivity of the fluid and hence the effectiveness of the process of introducing voltage pulses into the fluid to be improved.

The laser preferably emits light at a frequency selected from a range with a lower limit of 300 THz, in particular 410 THz, and an upper limit of 550 THz, in particular 490 THz.

Another option in this respect is for the laser to be connected to a device for generating intermittently occurring light, and in the case of one embodiment the laser emits light pulses with a pulse duration selected from a range with a lower limit of 20 μs, in particular 33 μs, and an upper limit of 100 μs, in particular 50 μs. Similarly to the embodiment of the invention using intermittently occurring light from the light-emitting diode(s), it was found that in practice, intermittently occurring laser light improves the heating performance of the device and the heating system, in particular at a frequency within the specified range.

The pulse generator is preferably provided with a regulating and/or control module in order to obtain greater accuracy of the voltage pulses transmitted to the fluid, in particular the shape of the voltage pulses. As an alternative to this, the pulse generator may also be connected to an external regulating and/or control device for the same purpose.

Based on a preferred embodiment of the heating system, the heat exchanger is provided in the form of a radiator, in which case this heating system is designed in particular for heating the ambient air of a building.

To provide a clearer understanding, the invention will be described in more detail with reference to the appended drawings.

These are schematically simplified diagrams illustrating the following:

FIG. 1 illustrates an embodiment of a device for heating a fluid;

FIG. 2 shows a heating system;

FIG. 3 shows a variant of a voltage pulse pattern;

FIG. 4 illustrates how the choice of material for the two other electrodes influences the degree of efficiency of the device;

FIG. 5 illustrates how activating the two other electrodes influences the degree of efficiency of the device;

FIG. 6 illustrates how applying variable voltage pulses to the fluid affects the degree of efficiency.

Firstly, it should be pointed out that the same parts described in the different embodiments are denoted by the same reference numbers and the same component names and the disclosures made throughout the description can be transposed in terms of meaning to same parts bearing the same reference numbers or same component names. Furthermore, the positions chosen for the purposes of the description, such as top, bottom, side, etc., relate to the drawing specifically being described and can be transposed in terms of meaning to a new position when another position is being described.

FIG. 1 illustrates a device 1 as proposed by the invention for heating a fluid, preferably water. It comprises a housing 2, comprising a housing shell 3, as well as a housing base 4 and a housing cover 5. The housing 2, i.e. the housing shell 3 and/or the housing base 4 and/or the housing cover 5, are preferably made from a dielectric material, for example a plastic, e.g. PE, PP, PVC, PS, Plexiglas etc.

As may be seen from FIG. 1, both the housing base 4 and the housing cover 5 are each screwed by means of an internal thread in the housing shell 3—a thread 6 is provided in each case at each of the two end regions 7, 8 of the housing shell 3—and a co-operating external thread on the housing base 4 and on the housing cover 5 to the housing shell 3 so that the housing base 4 and the housing cover 5 can be removed from the housing shell 3. Instead of the screw connections, it would naturally also be possible to enable this removal by simply sliding the housing base 4 or housing cover 5 into the housing shell 3, in which case care must be taken with this embodiment to ensure that the requisite tight seal is obtained, e.g. by providing sealing rings or similar, such as O-rings. In addition, however, it is also possible for the housing base 4 and/or the housing cover 5 to be disposed in the housing shell 3 by means of a press-fit connection or to be connected to it by some other means, e.g. welding, etc. Another option is one where only the housing base 4 or only the housing cover 5 can be removed from the housing shell 3. Yet another option is for the housing 2 to be designed as an integral part with the housing base 4 and/or housing cover 5.

Based on the embodiment of the device 1 illustrated in FIG. 1, the housing 2 is cylindrical in shape. Naturally, however, it would also be possible for the housing 2 to be of a different three-dimensional shape, e. g. cubic, etc. The cylindrical design enables the flow resistance opposing a fluid 9 conveyed through the device 1, in particular water, to be reduced.

The housing cover 5 has a recess along a longitudinal mid-axis 10. e.g. in the form of a bore, serving as an inlet opening 11 for the fluid 9 into the device 1, i.e. into a reaction chamber 12 of the device 1.

An outlet opening 13 in the form of an axial bore is provided in the housing base 4, ensuring that the fluid 9 is able to drain out of the reaction chamber 12.

However, both the inlet opening 11 and the outlet opening 13 may be disposed at a different point in the housing 2 of the device 1, for example in the housing shell 3, or radially in the housing base 4 or housing cover 5, in order to impart a tangential flow to the incoming fluid 9.

Alternatively, more than one inlet opening 11 and/or more than one outlet opening 13 could also be provided, in which case an opening in both the axial and/or radial direction would be possible, for example one or more inlet openings 11 in the axial direction and one or more inlet openings 11 in the radial direction and/or one or more outlet openings 13 in the axial direction and one or more outlet openings 13 in the radial direction.

At least one anode 14 and at least one cathode 15 are disposed in the reaction chamber 12. The anode 14 is preferably of a basket-shaped design and the at least one cathode 15 is disposed at least partially inside the space defined by the anode 14, as illustrated in FIG. 1. To facilitate through-flow of the fluid 9, the anode 14 may be provided with one or more orifices 17 in an end region 16 facing the housing base 4, preferably oriented in the radial direction so that the fluid 9 leaves the region inside the reaction chamber 12 defined by the anode 14 deflected in the direction perpendicular to the longitudinal mid-axis 10. However, another option is for the anode 14 to be based on a lattice-type design or, alternatively or in addition to the orifice 17 or orifices 17, such orifices could also be provided in the part of the anode 14 facing the container base 4, in other words the “base” of the basket-shaped anode 14. In this connection, it is possible for the anode 14 as well as the cathode 15 to be of a bar-shaped design in one embodiment. Also, several anodes 14 and cathodes 15 may be provided, in which case it is preferable to opt for an alternating arrangement of the anodes 14 and cathodes 15, thereby forming pairs comprising an anode 14 and a cathode 15.

The at least one anode 14 is electrically conductively connected to a positive pole 18 and the at least one cathode 16 to a negative pole 19 of a pulse generator 20.

The distance 25 between the cathode 15 and the anode 14 is at least 5 mm, in particular at least 7 mm.

As illustrated in FIG. 1, the anode 14 in this embodiment is disposed in the reaction chamber 12 at a distance apart from the housing base 4. To obtain this spacing, a dome-shaped shoulder 21 is provided in the housing base 4 in the region of the outlet opening 13 for the fluid 9 from the reaction chamber 12, which can be used to adjust the height of the at least one anode 14. In particular, this shoulder 21 is in turn of a rotationally symmetrical, bolt-shaped design and is retained in a central bore 22 in the housing base 4.

However, this shoulder 21 may also be based on any other geometric shape, for example a prism, in which case this bore 22 will be of a shape matching the external circumference of the shoulder 21.

It is also possible that this shoulder 21 does not extend through the housing base 4 and instead is placed on it, e.g. is glued to it or connected to the housing base 4 by some other joining technique, such as welding for example. In this example of an embodiment, this shoulder 21 is provided with an external thread 23, which locates in an internal thread 24 of the bore 22. This enables the height of this shoulder 21 to be adjusted to a certain degree so that a distance 25 between the anode 14 and cathode 15 can be adjusted, in other words the depth by which the cathode 14 extends into the basket-shaped anode 14 in this embodiment.

In addition to screwing the shoulder 21 in and out, another option is to design it so that it slides into the bore 22, thereby offering another way of adjusting this distance 25.

Along the course of the longitudinal mid-axis 10, this shoulder 21, which is preferably also made from a dielectric material, has an opening 26 which not extend in the direction of the longitudinal axis 10 and which is disposed in the flow direction of the fluid 9 (arrow 27) behind the opening 10 in the housing base 4.

At least one radial bore 28 is provided in the shoulder 21 in the region of the housing base 4, through which the fluid 9 is able to flow out of the reaction chamber 12. However, it would also be possible for the outlet opening 13 to be disposed not centrally in the housing base but off-center and adjacent to the mount for the shoulder 21 in the housing base, in which case this/these radial bore(s) 28 can be dispensed with. However, the advantage of the first of the above-mentioned variants is that the dwell time of the fluid 9 in the reaction chamber 12 can be lengthened, which is of advantage in terms of smoothing the fluid 9 in the context of the invention. Another option is to provide several radial bores 28 at different heights in the shoulder 21.

In this respect, it is possible for the housing base 4 and the shoulder 21 to be of an integral design in one embodiment, in which case, the height adjustment and hence the adjustment of the distance 25 can be obtained by screwing the housing base 4 into the housing shell 3.

The anode 14 may also be designed so that it at least partially surrounds the shoulder 21. Towards the bottom, i.e. in the direction towards the housing base 4, the anode 14 in this variant may be fixed in its vertical position by an appropriate fixing means, e.g. a nut or a circumferentially extending web or such like. In the simplest case, the anode 14 may sit on this fixing means so that it can be removed. However, it may naturally also be connected to this fixing means.

Another option is one where the anode 14, although based on a basket-shaped design, extends only in the direction towards the housing base 4. In this case, the cathode 15 has a surface extension extending parallel with the base of the anode 14, although it could also be fitted with its active surface extending horizontally only as opposed to the vertical orientation of this surface illustrated in FIG. 1.

The cathode 15 in this embodiment is likewise cylindrical. The cathode 15 is also retained in an axial bore 29 of the housing cover 5, and this axial bore 29 may naturally have a bigger diameter than the inlet opening 11 for the fluid 9.

This cathode 15 is preferably designed so that it can be screwed into or inserted in the axial bore 29. Alternatively, it would naturally also be possible for the cathode 15 to be connected to the housing cover 5 so that it cannot be moved.

To enable the fluid 9 to enter the reaction chamber 12, this cathode 15 may have a centrally disposed, continuous bore 30 in the flow direction of the fluid 9 (arrow 26) adjoining the inlet opening 11.

At this stage, it should be pointed out that the term bore is used in these descriptions of the subject matter but it would naturally be possible to choose different geometries for the object inserted in it and these bores may therefore generally be termed recesses with cross-sections adapted accordingly.

The cathode 15 may be entirely or partially covered by the housing cover 5 in the radial direction, in which case it is of advantage to provide a co-operating bore ore recess in the housing cover 5 with a bigger diameter than the axial bore 29, to enable a cathode chamber to be provided in the region of the cathode 15, as indicated by broken lines in FIG. 1. The housing cover 5 may also cover the cathode 15 in the direction towards the reaction chamber 12.

It would also be possible to provide at least one inlet opening 11 in an off-center disposition in the housing cover 5 so that the fluid does not have to flow through the cathode 15 and hence the axial bore 29.

Another option is for the cathode 15 to be closed in the bottom end region pointing in the direction towards the container base 4, in which case at least one radial bore is provided in the cathode 15 to allow the fluid 9 to pass into the reaction chamber 12.

As already mentioned, it is possible to provide several individual anodes 14 and several individual cathodes 15 in the reaction chamber 12, for example in the form of electrode plates or lattice-type electrodes, in which case these may optionally form packets.

Generally speaking, the anode 14 and the cathode 15 may be disposed one after the other in the flow direction of the fluid 9 or adjacent to one another.

Another option is not to dispose the housing base 4 and/or housing cover 5 in an inner bore of the housing shell 3 but conversely, to dispose them extending externally on the housing shell 3 in the manner of a push-on or screw-on cover 5.

The size of the reaction chamber 12 is variable, especially as regards the desired heating power of the device 1, which may be 5 kW to 40 kW, for example.

This also enables the actual flow speed of the fluid 9 in the reaction chamber 12 to be influenced.

The housing base 4 and/or the housing cover 5 may have stud-type projections at its outer ends, for example to facilitate connection of the heat generator 1 to a heating circuit or similar. To this end, these stud-type projections of the housing base 4 and housing cover 5 may be provided with appropriate threads. Naturally, it would also be possible to use a standard screw connection with clamping nuts or similar, e.g. a conical face pipe union of the type known in the heating industry.

Based on one embodiment, it is possible for the shoulder 21 to extend through the housing base 4 so that it can be operated from outside, i.e. outside of the reaction chamber 12, for example in order to correct the set distance 25 between the anode 14 and cathode 15 subsequently or to set it from outside.

Yet another option is to enable the height of the cathode 15 to be adjusted as well as that of the anode 14 or to use a design in which only cathode 15 can be displaced in terms of its position relative to the anode 14.

In this respect, it should be pointed out that the displacement could naturally be motor-driven or may be done manually only, for which purpose the shoulder 21 may be provided with an appropriate drive, for example. This drive may be based on a micro-electronic design, given that the absolute distances of the displacement during operation of the device 1 are not that great but should be understood as being nothing more than fine adjustments provided the correct distance 25 between the anode 14 and cathode 15 was set during initial operation. It is merely a question of compensating for any heat expansion which might have occurred with a view to further improving or optimizing the efficiency of the device 1.

Depending on the desired power rating of the device 1, the distance 25 between the at least one anode 14 and the at least one cathode 15 may be selected from a range with a lower limit of 7 mm and an upper limit of 10 cm or with a lower limit of 10 mm and an upper limit of 5 cm, the energy yield within this range being surprisingly high.

Both the anode 14 and the cathode 16 are usually made from a metal material.

The anode 14 may also be mounted in the housing in a different manner, for example likewise by means of the container cover 5, in which case the shoulder 21 can be dispensed with so that the region of the reaction chamber 12 after the electrodes can be made bigger or the housing made to a more compact design. Another option is for the anode 14 to be supported on a projection of the housing shell 3 pointing in the direction towards the longitudinal mid-axis 10.

The flow direction of the fluid 9 in terms of the intake may also be reversed, in which case this fluid 9 is fed in through the shoulder 21. To this end, an outlet opening may be provided in the anode 14 in the region where it adjoins the shoulder 21, via which the fluid 9 is fed into the region between the anode 14 and cathode 15. After flowing through this region, the fluid 9 is deflected in the region of the container cover 5 and fed back out of the reaction chamber 12 via at least one of the off-center outlet openings in the container base.

FIG. 2 illustrates the preferred possible application of the device 1 proposed by the invention. It is disposed in the circulation circuit of a heating system 31, e.g. a central heating system or a radiator 32. The radiator 32 may be made from any material, in particular stainless steel, copper or similar.

The device 1 further comprises the pulse generator 20. Naturally, other devices may be provided as necessary, such as at least one pump 33, at least one expansion tank 34, optionally a gas absorber 35, over-pressure safety features, control and measuring devices, etc., of the type known from heat engineering in the central heating sector. It would naturally also be possible to incorporate other control units 37.

The pulse generator 20 may be based on an electro-mechanical or electronic design. In the case of an electro-mechanical design, the pulse generator comprises an electric motor, a voltage pulse generator and a pump, in particular a hydraulic pump, these elements of the pulse generator 20 being disposed in the specified order on a common shaft. By contrast with the electro-mechanical pulse generator 20, the electronic pulse generator 20 is preferably of a modular design, and in a first power-feed module, e.g. a transformer, the electrical energy fed in from the grid or other power sources, e.g. accumulator, etc., is galvanically separated from the earthed power system. In the situation where alternating current is fed in, the supplied energy is optionally rectified in a rectifier module, e.g. with conventional rectifier elements known from the prior art. A supply module is conductively connected to the power-feed module or rectifier module, by means of which the continuous direct voltage is transformed into a pulsing direct voltage. This pulsing direct voltage is then applied via the anode 14 and cathode 15 to the fluid 9 in the gap between the electrodes. For regulating and/or control purposes, it is preferable to provide a regulating and/or control module comprising individual capacitors, transistors, at least one IGBT, which in the case of one embodiment may be provided in the form of a circuit board, for example. This regulating and/or control module regulates and/or controls pulse widths, pulse durations as well as the repeat frequency of the voltage pulses, for example. To this end, a temperature taken from a temperature regulating circuit may be applied as the regulating criterion, and this temperature regulating circuit receives data based on the temperature of the fluid 9, in particular the desired temperature of the fluid 9 in the heating system 31. In this heating system 31, it is possible to provide thermostats as temperature sensors of a type known per se.

Other input variables used for regulating purposes might include chemical and physical parameters, for example the pH value of the fluid 9 or a pressure or a concentration of a chemical additive for the fluid 9, for example a lye, or the electrical conductivity of the fluid 9.

The voltage pulses can therefore be adjusted in terms of both pulse shape and amplitude, and in particular the steepness of the flanks (dU/dt) of the voltage pulses can be adjusted and regulated from the pulse generator 20, in particular the rising flank and/or the trailing flank. It is therefore possible to set up voltage pulses with a steeply rising and flat or gently trailing flank, in particular rectangular pulses.

As already mentioned, this electronic pulse generator 20 may be supplied with primary energy, i.e. electric current, directly from the supply network of the power supplier. It would also be possible to feed in different signal shapes with different frequencies via an intermediate circuit from any power source, for which purpose transistors etc., known from the prior art are used in the electronic pulse generator 20 in order to obtain the ultimately desired pulse shape.

In order to prevent overheating of the pulse generator 20, it may be provided with an appropriate cooling module, for example in the form of cooling ribs, e.g. made from aluminum sections.

The operating mode of the device 1 can be summarized as follows. The pulse generator 20 is switched to the supply network, i.e. the power network. The voltage pulses generated by the latter are transmitted via the anode 14 and cathode 15 to the fluid 9 in the flow circuit of the heating system 31, where they generate the desired heat in the fluid 9. As this takes place, the fluid 9 is kept in circulation by the pump 35, which may be provided as a component of the electro-mechanical pulse generator 20 on the one hand or, if using an electronic pulse generator, as a separate component of the heating system 31. The fluid 9 is preferably circulated in a closed circuit through the circulation units of the heating system 31 and hence also through the device 1, in particular its reaction chamber 12.

At this stage, it should be pointed out that instead of a radiator 32, it would also be possible to use other types of heat exchanger, for example plate heat exchangers with a large surface area, tube heat exchangers, etc., where the heat from the fluid primarily heated by the device 1 is transmitted to a secondary fluid in a known manner, in order to heat houses, industrial installations or similar, for example.

It has proved to be of advantage if the fluid 9 has a basic medium added to it so that it has a basic pH value. In this respect, the pH value may be selected from a range with a lower limit of 7.1 and an upper limit of 12 or more especially preferably with a lower limit of 9 and an upper limit of 11. In order to create the basic pH values, any basic medium may be used in principle, but particularly preferred are caustic soda, potash, calcium hydroxide or calcium carbonate.

In terms of pulse frequencies for the voltage pulses, it has proved to be of particular advantage to opt for frequencies selected from a range of with an upper limit of 500 Hz and a lower limit of 100 Hz, in particular with an upper limit of 300 Hz and a lower limit of 150 Hz.

The pulse duration of the voltage pulses may be selected from a range with a lower limit of 10 μs and an upper limit of 250 μs, in particular from a range with a lower limit of 40 μs and an upper limit of 200 μs.

The pulse amplitude of the voltage pulses may be selected from a range with a lower limit of 330 V and an upper limit of 1500 V, in particular from a range with a lower limit of 500 V and an upper limit of 1200 V.

The pulse pauses between the voltage pulses may be selected from a range with a lower limit of 2 μs and an upper limit of 20 μs, in particular from a range with a lower limit of 5 μs and an upper limit of 8 μs.

Based on one particular embodiment of the invention, the pulse generator 20 is configured to emit variable voltage pulses. By this is meant that the pulse frequency and/or the pulse duration and/or the pulse pauses and/or the amplitude of the voltage pulses may vary over time so that the voltage pulses are not emitted in a regular pattern. In this respect, FIG. 3 illustrates a sequence of rectangular pulses with a variable pulse configuration in this context. The parameters for the voltage and pulse duration are selected from the ranges specified above. Since this is merely one example, no specific values are given in the diagram. It is merely intended to illustrate a pattern for voltage pulses.

It is also possible that within a group of consecutive voltage pulses, the voltage does not drop to zero but remains at a pre-definable level after a voltage pulse before the next voltage pulse follows.

Naturally, the example illustrated in FIG. 3 is merely intended to represent different voltage pulse patterns. The amplitude of the voltage pulses, the duration of the voltage pulses as well as the pulse pauses may be selected from the ranges specified above.

In order to achieve this, the pulse generator 20 may comprise a random number generator or alternatively appropriate software means may be provided for this purpose.

As already mentioned, it is preferable to use rectangular voltage pulses. However, it would be possible within the scope of the invention to use voltage pulses with a steep rising flank of at least 25 V/μs.

The pulse frequency of the voltage pulses may also be selected from a range with a lower limit of 20 Hz, in particular 800 Hz, preferably 2530 Hz, and an upper limit of 20 kHz, in particular 11 kHz.

The trailing flank of the voltage pulses may also be selected so that it is as steep as the rising flank, but it is possible to opt for other degrees of steepness of at least 15 V μs, although this is not the preferred variant of the invention.

As proposed by the invention, at least two other electrodes 38, 39 may also be disposed in the reaction chamber 12, which are electrically conductively connected to a power source 40. Based on an appropriate design, the power source 40 may also be disposed in the pulse generator 20 and in the case of this embodiment, care must be taken to ensure that power is supplied to the two other electrodes 38, 39 without any mutual influence on the power supply of the electrodes used to generate the voltage pulses between the anode 14 and the cathode 15.

Naturally, it would also be possible within the scope of the invention to provide more than two other electrodes 38, 39 in the reaction chamber 12, for example in the case of the embodiment illustrated in FIG. 1 extending to the left and right of the anode 14 and in the direction of the longitudinal extension 10, in which case the other electrodes 38, 39 are respectively supplied with electrical energy in pairs from the power source 40.

Another option is to design the two other electrodes 38, 39 with a cylindrical casing shape so that these two other electrodes 45, 46 are disposed at least partially surrounding the at least one anode 14 and the at least one cathode 15, for example.

In principle, though not preferred, another option is to provide only one other electrode 45 or 46, in which case the opposite electrode in this instance is formed by the at least one anode 14 or the at least one cathode 15 which, unlike the situation where a respective electrode pair is provided, can be connected via a regulating and/or control device. Accordingly, the following explanations should also be read with this in mind.

In particular, it is possible for these three, i.e. anode 14, cathode 15 and other electrode 45 or 46, to be disposed concentrically with one another and at least partially inside one another (the latter having different diameters).

Yet another possibility is for the at least one cathode 15 or the at least one anode 14 to have at least two electrically non-conductive regions connected to one another, namely a region for setting up the electrode pairing of anode 14—cathode 15, and a region for setting up the electrode pairing with the other electrode 45 or 46.

The other electrodes 38, 39 may be made from the same material or different material from one another. In any case, the two other electrodes 38, 39 are made from a metal or a metal alloy. Possible metals which might be used are, for example, Pd, Pt, Ti, Rh, Au, Ag, Ni, Cu, Ir, Fe, V, Nb, Ta and their alloys. During tests run on the device 1, however, it was found to be of advantage to use a silver alloy with a total of up to 25% by weight Ni and/or Nb and/or Ta, in particular a total of up to 15% by weight Ni and/or Nb and/or Ta, or a platinum alloy with a total of up to 20% by weight, in particular a total of 12% by weight, rhodium and/or Ni and/or Ir, to improve the degree of efficiency of the device 1 i.e. achieve better heating power of the device 1, as will be explained in more detail below. In this respect, it is also possible for at least one of the electrodes 38, 39 to have a substrate core comprising a metal substrate for the metals and alloys listed above, in which case it will be made from a less expensive metal or less expensive metal alloy, for example steel, and the metals or alloys listed above are then deposited on this substrate core, in particular galvanically, using a method known from the prior art.

As illustrated in FIG. 1, at least one of the two other electrodes 38, 39 is preferably disposed in the region of the anode 14. If the relative position of the anode 14 with respect to the cathode 15 is reversed so that the cathode 15 is disposed outside of the anode 14 in the reaction chamber 12, it is possible to provide at least one of the two other electrodes 38, 39 in the region of the cathode 15.

Although this is the preferred embodiment of the invention, it would naturally also be possible to dispose these at least two other electrodes 38, 39 in a different region of the reaction chamber 12, for example these other electrodes 38, 39 could be disposed underneath the anode 14 in FIG. 1, in the region formed between the anode 14 and the housing base 4. In any event, the disposition should be such that a free run exists between the two electrodes 38, 39 for the flow of fluid 9 and an arrangement of the two electrodes 38, 39 with the shoulder 21 lying in between is not desirable within the context of the invention.

A distance 41 between these two electrodes 38, 39 is preferably at most 10%, in particular at least 25%, of the length of the reaction chamber 12, i.e. of the longitudinal extension of the reaction chamber 12 in the direction of the longitudinal mid-axis 10 between the housing base 4 and the housing cover 5. The reaction chamber 12 is therefore formed by the region in which the at least one anode 14 and the at least one cathode 15 are disposed. The distance 41 is the shortest distance between these two electrodes 38, 39. In the embodiment illustrated in FIG. 1, this distance 41 is the distance between the two end regions of the two other electrodes 38, 39.

If the two other electrodes 38, 39 are disposed adjacent to one another in the device 1, i.e. in the reaction chamber 12, in order words parallel with one another, this distance 41 is the distance formed between the two surfaces of the electrodes 38, 39 pointing towards one another.

As illustrated in FIG. 1, these two other electrodes 38, 39 are preferably of a bar-shaped design. A diameter 42 of the bar-shaped electrodes 38, 39 has a dimension of at most 30% of the smallest dimension of the at least one cathode 15. In the context of the invention, however, and for the reasons outlined above, it is preferable if this diameter 42 has a maximum value of 20% of the smallest dimension of the at least one cathode 15.

Although, within the scope of the invention, there are more different possibilities as to how the at least two other electrodes 38, 39 are disposed in the reaction chamber 12, it is preferable if these two other electrodes 38, 39 are disposed in the direction of the longitudinal extension 10 of the housing and coaxially with one another in the housing 2, as illustrated in FIG. 1.

Furthermore, the electrodes 38, 39 need not necessarily be in an upright position as illustrated in FIG. 1 and they could also be placed in the reaction chamber 12 in a lying position, i.e. with their biggest longitudinal extension oriented at least approximately perpendicular to the longitudinal mid-axis 10 of the device 1.

The power source 41 for the at least two other electrodes 38, 39 is preferably a constant voltage source of the type known from the prior art. If an alternating voltage is used as the primary power source, this power source 41 preferably has a rectifier.

In one particularly preferred embodiment of the invention, the electrodes 38, 39 are surface-activated before they are built into the reaction chamber 12 of the device. To this end, voltage pulses with an amplitude selected from a range of from 5 V to 50 V are applied to the two electrodes 38, 39 in an electrolyte bath. The pulse duration of the voltage pulses is selected from a range with a lower limit of 1 μs and an upper limit of 10 μs. The current intensity is selected from a range with a lower limit of 2000 A and an upper limit of 8000 A. The electrolyte bath in which this activation takes place preferably contain water glass (Na₂SiO₃), at least one lye, in particular KOH, distilled or de-ionized water, and optionally Na₂SO₃ and/or K₂SO₄, The proportion of water glass may be selected from a range of from 0.05% by weight to 10% by weight, in particular 0.1% by weight to 1% by weight. The proportion of lye may be selected from a range of from 0.05% by weight to 5% by weight, in particular 0.1% by weight to 5% by weight. The rest making up 100% by weight is water, provided the electrolyte bath contains no other additives, for example those mentioned above, in which case their proportion is limited to 10% by weight.

As a result of this activation, the surface of the electrodes 38, 39 is changed.

In one embodiment, it is possible to deposit the metals or alloy on the substrate core mentioned above at the same time as the activation takes place.

In the case of another embodiment of the device proposed by the invention, an electrolyte is added to the fluid 9, in particular the water. The electrolyte used may be a conductive salt that is soluble in water or in the fluid, in a manner known from the prior art. In addition to water, however, the electrolyte preferably contains KOH in a proportion of at most 5% by weight.

As already explained above, if water is used as the fluid 9, it may be preferable to add a lye or base or at least one electrolyte to it. This increases the conductivity of the water due to the presence of ions, and the ions also originate from the two other electrodes 38, 39. In this case, it has proved to be of advantage if at least one laser 43, i.e. the light-emitting part of a laser 43, is disposed in the reaction chamber, as schematically illustrated in FIG. 1. In particular, this light-emitting part of the laser 43 is in turn disposed in the housing shell 3 or alternatively this light-emitting part of the laser 43 may be shifted farther in the direction towards the longitudinal mid-axis 10 of the reaction chamber 12, for which purpose appropriate devices may be provided in the housing shell 3, for example plug-in sleeves, etc. Alternatively, it would also be possible to make the housing shell 3 from a transparent material and beam the laser light into the reaction chamber 12 from outside.

The laser 43 is preferably a red light laser and the laser 43 preferably emits light at a frequency selected from a range with a lower limit of 300 THz and an upper limit of 550 THz.

Based on one embodiment, the laser 43 may emit intermittent light, in which case the laser 43 has an appropriate device for generating this intermittent light or is connected to one. A pulse duration of the laser light pulse may be selected from a range with a lower limit of 20 μs, in particular 33 μs, and an upper limit of 100 μs, in particular 50 μs.

FIG. 4 illustrates how the material chosen for the two electrodes 38, 39 affects the degree of efficiency of the device 1.

By degree of efficiency in the context of the invention is meant that the ratio of energy picked up to the energy emitted is regarded as heating power.

FIG. 4 shows a bar denoted by 44 using PtNi5 as electrode material, a bar 45 using Pt as electrode material, a bar 46 using an alloy based on the composition AgNi5 as electrode material, a bar 47 using Ni as electrode material and a bar 48 using steel as electrode material.

As may be seen from FIG. 4, the alloy AgNi5 used by preference as electrode material has a significantly higher degree of efficiency than electrodes made from the other materials listed. In this respect, the difference in the degree of efficiency between PtNi5 and AgNi5 as electrode material (bar 44) is apparently only slight but this difference still results in an increase in the degree of efficiency of the device 1 representing 3% to 5% simply by using the electrode material AgNi5, which makes the device 1 more economical and in particular offers the advantage of reducing environmental pollution.

FIG. 5 illustrates what effect activating the surface of the two electrodes 38, 39 has on the degree of efficiency of the device 1. One bar 49 represents the use of non-activated AgNi5 and one bar 50 represents the same electrodes but with an activated surface. As illustrated, activating the surface in the manner described above results in a significant increase in the degree of efficiency compared with electrodes made from the same composition but with non-activated surfaces.

FIG. 6 illustrates what effect applying variable voltage pulses to the fluid 9 has in terms of the degree of efficiency of the device 1 within the meaning of the invention, although again, specific values have been omitted because the intention is merely to draw a relative comparison between the two variants. With the exception of the voltage pulses, all other parameters used for the two variants are the same. One curve 51 plots the degree of efficiency over time using a constant voltage pattern and one curve 52 plots the degree of efficiency of the device 1 using variable voltage patterns such as those illustrated in FIG. 3 for example or described above.

As clearly illustrated by FIG. 6, a higher degree of efficiency is obtained by feeding variable voltage pules into the reaction chamber 12, thereby making the device 1 more economic to run. It was also found, as also demonstrated by curve 52, that fluctuation in the degree of efficiency is significantly lower than in the case of curve 51.

As known from the prior art, the heating system 31 may be operated at a pressure of between 2 bar and 4 bar in the primary circuit, for example. However, it would also be possible for the heating system 31 to be operated without pressure in the primary circuit with a temperature of the fluid 9 close to the boiling point of the fluid 9.

Although it has been mentioned at several points that the heating system 31 or device 1 is used to heat houses, this generally applies to the generation of heat irrespective of the purpose for which this heat will ultimately be used. In order to increase the heating power if necessary, it would be possible to connect several devices 1 one after the other, i.e. in series, in the heating system 31.

List of reference numbers 1 Device 2 Housing 3 Housing shell 4 Housing base 5 Housing cover 6 Thread 7 End region 8 End region 9 Fluid 10 Longitudinal mid-axis 11 Inlet opening 12 Reaction chamber 13 Outlet opening 14 Anode 15 Cathode 16 End region 17 Orifice 18 Positive pole 19 Negative pole 20 Pulse generator 21 Shoulder 22 Bore 23 External thread 24 Internal thread 25 Distance 26 Opening 27 Arrow 28 Radial bore 29 Axial bore 30 Bore 31 Heating system 32 Radiator 33 Pump 34 Expansion tank 35 Gas absorber 36 Measuring device 37 Control unit 38 Electrode 39 Electrode 40 Power source 41 Distance 42 Diameter 43 Laser 44 Bar 45 Bar 46 Bar 47 Bar 48 Bar 49 Bar 50 Bar 51 Curve 52 Curve 

1. Device (1) for heating a fluid (9), with a housing (2) comprising a housing shell (3), a housing base (4) and a housing cover (5), with at least one inlet opening (11) and at least one outlet opening (13) for the fluid (9), and at least two electrodes, in particular at least one anode (14) and at least one cathode (15), are disposed in the housing (2) at a distance (25) apart from one another, which are each electrically conductively connected to a pole of at least one pulse generator (20), wherein the pulse generator (20) is configured to emit variable voltage pulses.
 2. Device (1) according to claim 1, wherein the pulse generator (20) generates voltage pulses with an amplitude selected from a range with a lower limit of 330 V and an upper limit of 1500 V.
 3. Device (1) according to claim 1, wherein the pulse generator (20) comprises a random number generator.
 4. Device (1) according to claim 1, wherein the pulse generator (20) generates voltage pulses with a steep rising flank of at least 25 V/μs.
 5. Device (1) according to claim 1, wherein the pulse generator (20) generates rectangular voltage pulses.
 6. Device (1) according to claim 1, wherein the pulse generator (20) emits voltage pulses at a pulse frequency selected from a range with a lower limit of 20 Hz and an upper limit of 20 kHz.
 7. Device (1) according to claim 1, wherein the pulse generator (20) emits voltage pulses with a pulse duration selected from a range with a lower limit of 2 ns and an upper limit of 10 μs.
 8. Device (1) according to claim 1, wherein the pulse generator (20) generates voltage pulses with a pulse pause selected from a range with a lower limit of 2 μs and an upper limit of 20 μs.
 9. Device (1) according to claim 8, wherein the pulse generator (20) is configured to generate variable pulse pauses.
 10. Device (1) according to claim 1, wherein one other electrode (38 or 39), preferably at least two other electrodes (38, 39) is or are provided in the reaction chamber (12), which are electrically conductively connected to a power source (40).
 11. Device (1) according to claim 10, wherein the other electrode (38 or 39) or the at least two other electrodes (38, 39) is/are made from a material selected from a group comprising Pd, Pt, Ti, Rh, Au, Ag, Ni, Cu, Ir, Fe, V, Nb, Ta and their alloys.
 12. Device (1) according to claim 10, wherein the other electrode (38 or 39) or at least one of the two other electrodes (38, 39) is/are disposed in the region of one of the at least two electrodes, in particular the anode (14) or the cathode (15).
 13. Device (1) according to claim 10, wherein a distance (41) between the at least two other electrodes (38, 39) is at least 10% of the length of a reaction chamber (12) defined by the housing (2).
 14. Device (1) according to claim 10, wherein the other electrode (38 or 39) or the at least two other electrodes (38, 39) are of a bar-shaped design with a diameter (42) of at most 30% of the smallest dimension of at least one of the at least two electrodes, in particular the at least one cathode.
 15. Device (1) according to claim 10, wherein the power source (40) for the other electrode (38 or 39) or the at least two other electrodes (38, 39) is a constant voltage source.
 16. Device (1) according to claim 10, wherein the other electrode (38 or 39) or the at least two other electrodes (38, 39) are activated in an electrolyte bath with voltage pulses with an amplitude selected from a range of from 5 V to 50 V (direct current) and a pulse duration selected from a range of 1 μs to 10 μs at a current intensity selected from a range with a lower limit of 2000 A and an upper limit of 8000 A.
 17. Device (1) according to claim 1, wherein the housing (2) contains water with an electrolyte.
 18. Device (1) according to claim 17, wherein the electrolyte contains water glass (Na₂SiO₃), at least one lye, in particular KOH, distilled or de-ionized water, and optionally Na₂SO₃ and/or K₂SO₄.
 19. Device (1) according to claim 10, wherein the at least two other electrodes (38, 39) are disposed in the direction of a longitudinal extension (10) of the housing (2) and coaxially with one another in the housing (2).
 20. Device (1) according to claim 1, wherein at least one of the electrodes, in particular the anode (14), is of a basket-shaped design.
 21. Device (1) according to claim 20, wherein at least one of the least two electrodes is disposed at least partially inside the basket-shaped electrode, in particular the at least one cathode (15) is disposed at least partially inside the basket-shaped anode (14).
 22. Device (1) according to claim 1, wherein the distance (25) between the at least two electrodes, in particular between the cathode (15) and the anode (14), is at least 5 mm.
 23. Device (1) according to claim 1, wherein the housing shell (3) is cylindrical in shape.
 24. Device (1) according to claim 1, wherein at least one of the least two electrodes is or are disposed in the housing (2) so as to be relatively displaceable towards the other electrode, in particular the anode (14) is displaceable relative to the cathode (15) and/or the cathode (15) is displaceable relative to the anode (14).
 25. Device (1) according to claim 1, wherein at least one laser (43) is disposed in the reaction chamber (12).
 26. Device (1) according to claim 25, wherein the laser (43) emits light at a frequency selected from a range with a lower limit of 300 THz and an upper limit of 550 THz.
 27. Device (1) according to claim 25, wherein the laser (43) is connected to a device for generating an intermittently occurring light.
 28. Device (1) according to claim 27, wherein the laser (43) emits light pulses and a pulse duration is selected from a range with a lower limit of 20 μs and an upper limit of 100 μs.
 29. Device (1) according to claim 1, wherein the pulse generator (20) has a regulating and/or control module or is connected to a regulating and control device.
 30. Heating system (31) comprising at least one device for conveying a first fluid (9), at least one device (1) for heating of the fluid (9), at least one heat exchanger in which the heat generated by the fluid (9) is transmitted to another fluid, wherein the at least one device (1) for heating a fluid (9) is as defined according to claim
 1. 31. Heating system (31) according to claim 30, wherein the heat exchanger is provided in the form of a radiator (32).
 32. Use of the device (1) for heating a fluid (9) according to claim 1 to heat a building. 